A tip is to switch the vocals to static. this gives you the opportunity to see what lyric is coming up before it actually does. so when it does come up you can just concentrate on the pitch and keep looking at the instrument you are playing "notes".
I did this via the overall game settings, but it still scrolled when i got in game.
So the best way to do this is once you're in the actual game (like when a song has loaded) THEN go to switch to static vocals and it will be that way for the rest of the game.









